We have found a bug in the multiplication, *, procedure of our version of
Scheme. The deeper root of the problem is apparently in the primitive for
multiplying fixnums. Multiplying 0 times a negative number results in
#[(undefined-type-code 81) 0] . It is easy enough to work around this, but
someone maintaining MIT Scheme might look into this if it hasn't already
been fixed. The version we're using is the VAX/VMS version of MIT Scheme,
Microcode 6.1, Runtime 11.2, Features 1.1, Student 11.1, and is dated
Thursday May 31, 1985.